What is the recommended treatment and dosage for insomnia using Belsomra (suvorexant)?

Recommended Treatment and Dosage for Insomnia Using Belsomra (Suvorexant)

Belsomra (suvorexant) is recommended for the treatment of sleep maintenance insomnia at a starting dose of 10 mg taken once nightly, with the option to increase to a maximum of 20 mg if the lower dose is ineffective. 1, 2

Dosing Guidelines

• The recommended starting dose is 10 mg taken once per night within 30 minutes of going to bed (with at least 7 hours remaining before planned awakening) 2
• If the 10 mg dose is well-tolerated but not effective, the dose can be increased to a maximum of 20 mg taken once per night 2
• Take on an empty stomach, as food may delay the onset of action 2
• Lower doses (5 mg) should be considered when used with moderate CYP3A inhibitors 2

Special Population Considerations

• Dosage adjustment is recommended for obese patients, particularly obese women, due to increased drug exposure and risk of adverse effects 2
• No specific dosage adjustment is required based on age alone, as efficacy and tolerability are similar in adults <65 and ≥65 years 3
• Use with caution when combined with other CNS depressants, as dosage reduction of Belsomra and/or the other medications may be necessary 2

Efficacy Profile

• Belsomra is effective for sleep maintenance insomnia, with clinical trials showing:
  • Reduction in wake after sleep onset by 16-28 minutes compared to placebo 1
  • Improvement in total sleep time by approximately 10 minutes compared to placebo 1
• Belsomra works through a novel mechanism as a dual orexin receptor antagonist, unlike traditional sleep medications 4, 5
• The number needed to treat (NNT) for a clinically significant improvement in insomnia symptoms is approximately 8 3

Safety Considerations

• The most common adverse effect is somnolence, with a number needed to harm (NNH) of 28 for the 15-20 mg dose range 3
• Belsomra may impair driving skills and increase the risk of falling asleep while driving, particularly at the 20 mg dose 2
• CNS depressant effects may persist in some patients for several days after discontinuation 2
• Belsomra is contraindicated in patients with narcolepsy 2
• Unlike some other sleep medications, rebound insomnia and withdrawal effects were not observed after 3 or 12 months of nightly use 3

Clinical Pitfalls and Caveats

• Belsomra should not be used with strong CYP3A inhibitors 2
• Patients should be cautioned about next-day driving and activities requiring full mental alertness, especially at higher doses 2
• Belsomra is a Schedule IV controlled substance, though it may theoretically have lower addiction liability compared to other hypnotics due to its novel mechanism 5
• The FDA initially recommended lower doses (5-15 mg) than what the manufacturer proposed (15-40 mg) due to concerns about next-day somnolence and safety 6
• Avoid administration with or soon after a meal, as this may delay the onset of action 2